VM start, image build, and network/setup failures were hard to diagnose because bangerd emitted almost no lifecycle logs and the Firecracker SDK logger was discarded. This adds a daemon-wide JSON logger with configurable log level so failures leave breadcrumbs instead of only side effects.
Log the main daemon and VM lifecycle stages, preserve raw Firecracker and image-build helper output in dedicated files, and include those log paths in daemon status and returned errors. Bridge SDK logrus output into the daemon logger at debug level so low-level Firecracker diagnostics are available without making normal info logs unreadable.
Validation: go test ./... and make build. Left unrelated worktree changes out of this commit, including internal/api/types.go, the deleted shell scripts, and my-rootfs.ext4.
Replace the daemon's hand-rolled Firecracker process/socket client with the official firecracker-go-sdk while keeping the existing VM lifecycle and host-side disk and TAP setup intact.
Build machine configs through the SDK, launch Firecracker through a sudo process runner, resolve the real VM PID after startup, and use the SDK client for Ctrl-Alt-Del instead of raw REST calls. Drop the unused cached Firecracker state and add focused adapter tests for config and process-runner wiring.
Validated with go mod tidy, go test ./..., and make build. A live KVM/Firecracker smoke boot was not run in this environment.
